The present invention relates to gyrotron backward wave oscillator devices.
The electron cyclotron maser instability has been exploited as the basis for a new high power millimeter-wave tube called the gyrotron. The gyrotrons that have been developed include cavity oscillators, travelling wave amplifiers, and multi-cavity gyro-klystrons; and a number of studies describing the design and operation of such devices have been published. See, for example, V. A .Flyagin, A. V. Gapunov, M. I. Petelin and V. K. Yulpatov, IEEE Trans. Microwave Theory and Tech. MTT-25, 514 (1977); K. R. Chu, Phys. Fluids 21, 2354 (1978); Kwo Ray Chu, A. T. Drobot, V. L. Granatstein and J. L. Seftor, IEEE Trans. Microwave Theory and Tech. MTT-27, 178 (1979); and J. L. Seftor, V. L. Granatstein, Kwo Ray Chu, P. Sprangle and M. E. Read, IEEE J. Quant. Elec., QE-15, 848 (1979). However, the design of an operable and predictable gyrotron backward wave oscillator has not yet been achieved, insofar as we are aware, although gyrotron backward wave oscillations have been observed as an undesirable effect. Yet the design of an operable gyrotron backward wave oscillator which can be operated in a controlled and predictable manner as regards frequency output, is obviously desirable since such an oscillator would provide a high power source of radiation in the microwave and millimeter wave frequency region tunable over the entire useful frequency range of a waveguide mode.
An object of the present invention is to provide a gyrotron backward wave oscillator device which can be operated in a controlled and predictable manner.